Male prairie voles display mating-induced pair bonding indicated by preferences toward familiar partners and selective aggression toward a conspecific stranger, and thus serves as an excellent model for the study of the neurobiology of pair bonding. Central dopamine (DA) is implicated in pair bond formation in prairie voles. Several lines of evidence have indicated that DA, particularly DA in the amygdala (AMY), may play an important role in the regulation of aggression. The AMY is well known for its role in processing emotionally related cues including aggressive interactions, social recognition, and stress responses in a variety of mammalian species including voles. My recent neuroanatomical data illustrate a unique pattern of DA cells in the vole's AMY and activation of those cells during selective aggression. Further, there is an increase in AMY DA content in pair-bonded male prairie voles displaying selective aggression toward unfamiliar female prairie voles. In the present application, I propose to focus on the AMY to measure DA release and DA receptor mRNA and binding during selective aggression, and to examine the receptor-specific mechanisms underlying pharmacological effects of DA on mating-induced aggression in male prairie voles. This series of experiments will shed light on the neurochemical underpinnings of aggression.